Galatian posted: Gravity was not "known" for many centuries. It was observed that things fall down when nothing stops them. However, gravity was first hypothesized by Newton, who showed how it worked and that it could account for the motions of planets. Likewise, we see variation within and among species. Darwin only discovered why it works, and showed that it could account for common descent. The effects of gravity were certainly known for many centuries. However I never saw anyone use the word ‘known’ regarding gravity in the terms Galatian referred to it – except him. Who he was disputing, I don’t know. However it does need to be said that Newton was not the first to hypothesize about gravity! Before Newton were Pato, Eudoxus, Aristotle, Aristarchus, Ptolemy, Copernicus, Tycho Brahe, Kepler, and Galileo – at least. Newton formulated some ideas about gravity. But knowing exactly WHAT it is, is still up for grabs. Does this correspond with evolution? Not at all! We see gravity, whatever it is, work everyday. We depend on it! No one has seen evolution work outside of simple variations – none of which change the identity of the organism from its original classification above the species level. And since ‘species’ is a very arbitrary term, declaring a new ‘species’ is extremely subjective and has no relation to the actual change of form and function brought on by mutations and time and chance. All Darwin SAW was variation – specifically in pigeons, I believe – and that among birds bred in captivity! So not only was his famous ‘natural selection’ not involved, intelligent design (breeding) was! The leap from that to common descent was one of illogic and pure speculation – speculation which has not held up with increasing evidence available.